U.S. patent application number 11/165945 was filed with the patent office on 2006-12-28 for structure and system for occupant protection in a side impact automobile collision and methods of use thereof.
Invention is credited to Robert Philip Kaufman, Charles Newman Mock, Allan Tencer.
Application Number | 20060290160 11/165945 |
Document ID | / |
Family ID | 37566451 |
Filed Date | 2006-12-28 |
United States Patent
Application |
20060290160 |
Kind Code |
A1 |
Tencer; Allan ; et
al. |
December 28, 2006 |
Structure and system for occupant protection in a side impact
automobile collision and methods of use thereof
Abstract
A system for managing an occupant in an occupant compartment of
an automotive vehicle, a structure for use in an automobile, and
methods of use thereof are provided for protecting an occupant
during a near side impact collision.
Inventors: |
Tencer; Allan; (Seattle,
WA) ; Kaufman; Robert Philip; (Seattle, WA) ;
Mock; Charles Newman; (Seattle, WA) |
Correspondence
Address: |
WOODCOCK WASHBURN LLP
ONE LIBERTY PLACE, 46TH FLOOR
1650 MARKET STREET
PHILADELPHIA
PA
19103
US
|
Family ID: |
37566451 |
Appl. No.: |
11/165945 |
Filed: |
June 24, 2005 |
Current U.S.
Class: |
296/68.1 ;
296/187.12 |
Current CPC
Class: |
B60N 2/062 20130101;
B60N 2/42736 20130101 |
Class at
Publication: |
296/068.1 ;
296/187.12 |
International
Class: |
B60N 2/42 20060101
B60N002/42; B60N 2/427 20060101 B60N002/427 |
Claims
1. A structure for use in an automobile for protecting an occupant
during a near side impact collision, comprising: a lateral seat
track attached to said automobile and oriented substantially
perpendicular to a central longitudinal axis of said automobile, an
occupant seat operatively coupled to a substantially rigid frame
and said lateral seat track such that, during a near side impact
collision, an automobile door contacts said substantially rigid
frame or said occupant seat, and said substantially rigid frame and
said occupant seat translate laterally away from an impacting
vehicle and toward said central longitudinal axis, and a limiting
barrier disposed adjacent to said occupant seat and configured to
impede said lateral translation of said occupant seat during said
near side impact collision.
2. A structure as recited in claim 1 wherein said substantially
rigid frame further comprises a platform on which said seat is
mounted, said platform being attached to said lateral seat
track.
3. A structure as recited in claim 1 wherein said platform
comprises a substantially rigid frame on two or more sides and
bottom of said occupant seat.
4. A structure as recited in claim 1 wherein said substantially
rigid frame is external to said occupant seat.
5. A structure as recited in claim 1 wherein said substantially
rigid frame is internal to said occupant seat.
6. A structure as recited in claim 1 wherein said substantially
rigid frame remains intact following a lateral impact force between
about 5,000 N and about 15,000 N.
7. A structure as recited in claim 1 wherein said lateral seat
track is cantilevered.
8. A structure as recited in claim 1, further comprising a
restraint to maintain an occupant within said occupant seat as it
translates laterally following said near side impact collision.
9. A structure as recited in claim 8 wherein said restraint is
disposed between said occupant and said door, wherein said
restraint is hinged to said seat.
10. A structure as recited in claim 8 wherein said restraint is
disposed between said occupant and said limiting barrier.
11. A structure as recited in claim 1, further comprising shear
bolts to restrain lateral translation of said occupant seat.
12. A structure as recited in claim 11 wherein said shear bolts
release following a lateral impact force between about 2,000 N and
about 8,000 N.
13. A structure as recited in claim 1 wherein said limiting barrier
comprises a center console constructed of a crushable material.
14. A structure as recited in claim 13 wherein said limiting
barrier crushes following a lateral impact force between about
5,000 N and about 15,000 N.
15. A system for managing an occupant in an occupant compartment of
an automotive vehicle in an event of a near side impact collision,
comprising: restraint means for maintaining the occupant in an
occupant seat during a near side impact collision, means for
reacting to said collision by laterally displacing said occupant
seat toward a center of said occupant compartment, and means for
absorbing laterally directed kinetic energy of said occupant
seat.
16. A system as recited in claim 15 wherein said means for reacting
to said collision further comprises an occupant seat operatively
coupled to a substantially rigid frame and a lateral seat
track.
17. A system as recited in claim 16 wherein said substantially
rigid frame is disposed on two or more sides and bottom of said
occupant seat.
18. A system as recited in claim 16 wherein said occupant seat and
said substantially rigid frame translate laterally following
contact to said substantially rigid frame by an automobile door
during said near side impact collision.
19. A system as recited in claim 16 wherein said lateral seat track
is cantilevered.
20. A system as recited in claim 15 wherein said restraint means is
disposed between said occupant and said door, and said restraint
means is hinged to said seat.
21. A system as recited in claim 15 wherein said restraint means is
disposed between said occupant and said limiting barrier.
22. A system as recited in claim 15 wherein said means for
absorbing laterally directed kinetic energy is a limiting
barrier.
23. A system as recited in claim 22 wherein said limiting barrier
comprises a center console constructed of a crushable material.
24. A system as recited in claim 15, further comprising shear bolts
for restraining lateral translation of said occupant seat.
25. A method for managing an impact load from a near side impact
collision comprising: attaching a lateral seat track to an
automobile, said lateral seat track oriented substantially
perpendicular to a central longitudinal axis of said automobile,
operatively coupling an occupant seat to a substantially rigid
frame and said lateral seat track such that, during a near side
impact collision, an automobile door contacts said substantially
rigid frame or said occupant seat, and said substantially rigid
frame and said occupant seat translate laterally away from an
impacting vehicle and toward said central longitudinal axis, and
disposing a limiting barrier adjacent to said occupant seat, said
limiting barrier configured to impede said lateral translation of
said occupant seat and said substantially rigid frame during said
near side impact collision.
26. A method as recited in claim 25 wherein said lateral seat track
is cantilevered.
27. A method as recited in claim 25 wherein said limiting barrier
comprises a center console of a crushable material.
28. A method as recited in claim 25, further comprising providing
an occupant restraint.
29. A method as recited in claim 28 wherein said occupant restraint
is disposed between said occupant seat and said door, wherein said
restraint is hingedly connected to said seat.
30. A method as recited in claim 28 wherein said occupant restraint
is disposed between said occupant seat and said limiting
barrier.
31. A method for protecting an occupant in an automotive occupant
compartment from a near side impact collision comprising: providing
restraint means for maintaining the occupant in a seat and a
substantially rigid frame during a near side impact collision,
providing means for reacting to said collision by laterally
displacing said seat and said substantially rigid frame toward a
center of said occupant compartment, and providing means for
absorbing laterally directed kinetic energy of said seat and said
substantially rigid frame.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a system for managing an
occupant in an occupant compartment of an automotive vehicle and a
structure for use in an automobile for protecting an occupant
during a near side impact collision, and methods of use
thereof.
BACKGROUND OF THE INVENTION
[0002] Side impact crashes represented, in 2002, 26% of all fatal
collisions (second only to frontal crashes) with an estimated total
of 782,900 nonfatal and 9812 fatal injuries. Reports from a survey
of the National Automotive Sampling System (NASS) showed that
injuries to the chest occurred in 39.7% of surviving occupants,
followed by injuries to the head (25%), the pelvis (11.7%), and the
abdomen (8.4%). In a study of the 119 crashes currently entered in
the Crash Injury Research and Engineering Network (CIREN) database,
71 (60%) of occupants had pelvic fractures of at least AIS 2
(Abbreviated Injury Score). The mortality rate from motor vehicle
induced pelvic injury ranges from 8.6% to 50%, with 25%-35% of
survivors having unsatisfactory results after treatment. Compared
to patients in motor vehicle crashes without pelvic injury, those
with pelvic injury were significantly more injured, had higher
blood loss, longer hospital stays, more genitourinary injuries, and
higher mortality rates.
[0003] LC-I (lateral compression) pelvic fractures, involve
structures in direct contact with the incoming door. LC-I fractures
are stable, may be treated non-surgically and usually result in
little internal disruption. In contrast, LC-III fractures involve
not only injury to structures such as the sacrum or iliac wing and
pubic ramus on the door side, but also structures on the opposite
side. The LC-III fracture is highly unstable, involves rupture of
pelvic area blood vessels, has significant associated internal
hemorrhage, and damage to internal organs, and must be treated
surgically by stabilization of both the anterior and posterior
pelvic ring. Operative treatment of pelvic injuries, particularly
open reduction and internal fixation is associated with significant
surgical risk including deep infection, nerve injuries, and
malreduction. In a near side impact collision, pelvic fracture has
been described as occurring from direct contact with the intruding
door. Further studies have shown that LC-III pelvic fracture occurs
on the side opposite the door. This type of pelvic fracture implies
contact with some other structure in the vehicle. In several CIREN
crash investigations of near-side impacts, evidence was found of
hard contact of the pelvis through the belt buckle into the center
console.
[0004] Crash investigations and laboratory testing have also shown
that several factors can result in serious injury to the occupant's
chest and abdomen. Specifically, the armrest can act as a punch,
intruding into the chest wall causing rib fracture and internal
organ injuries. In addition, in many impacts, where a passenger car
door is hit high, near its upper border by the front end structures
of an SUV or truck, the top of the door tilts inward, accentuating
the contact of the door with the occupant's chest. Since the chest
is softer than the pelvis, the door and armrest will intrude into
the chest before the door contacts the pelvis and starts to
accelerate the occupant away.
[0005] A need exists in the art to better protect an occupant of an
automotive passenger compartment from serious injury resulting from
a near side impact collision when the striking vehicle is a truck
or sport utility vehicle which impacts the struck vehicle at
varying elevated positions and angles. A need exists in the art
further to reduce serious pelvic fractures and thoracic injuries to
vehicle occupants from near side impact collisions.
SUMMARY OF THE INVENTION
[0006] The present invention, in one embodiment, provides a
structure for use in an automobile for protecting an occupant
during a near side impact collision. An illustrative embodiment
comprises a lateral seat track attached to the automobile and
oriented substantially perpendicularly to a central longitudinal
axis of the automobile. An occupant seat is operatively coupled to
the lateral seat track such that, during a near side impact
collision, the occupant seat will move laterally away from an
impacting vehicle and toward the central longitudinal axis. A
limiting barrier is disposed adjacent to the occupant seat and is
configured to impede the lateral movement of the occupant seat
during the collision.
[0007] Other features of the present invention are described
below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 shows a front view of a structure for use in an
automobile for protecting an occupant during a near side impact
collision embodying the present invention.
[0009] FIG. 2 shows a side view of a structure for use in an
automobile for protecting an occupant during a near side impact
collision embodying the present invention.
[0010] FIG. 3 shows a front view of a structure for use in an
automobile for protecting an occupant during a near side impact
collision embodying the present invention after side impact.
DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
[0011] In a near side impact collision, pelvic fracture of an
automobile occupant can occur from direct contact with the
intruding door. Bilateral LC-III fractures, which include fractures
on the side opposite the door, imply contact with some other
structure in the vehicle. In several CIREN crash investigations of
near-side impact collisions, evidence was found for hard contact of
the pelvis through the belt buckle into the center console. Since
it appears that the center console can play a role in some pelvic
fractures, the secondary load from pelvic contact can be reduced by
changing the console structure so that it yields under loading by
the pelvis. Further extending this concept, if the seat were
permitted to move laterally in a controlled manner into the space
occupied by the crushed console, then primary impact loads on the
pelvis from door contact can also be reduced. In addition, if the
armrest is fixed to a side frame on the seat instead of to the
door, then the door will contact the seat side frame, protecting
the occupant's chest and abdomen.
[0012] The present invention provides, in several embodiments, a
structure for use in an automobile for protecting an occupant
during a near side impact collision, a system for managing an
occupant in an occupant compartment of an automotive vehicle in an
event of a near side impact collision, and a method for managing an
impact load from a near side impact collision. A near side impact
collision can occur in a two vehicle collision at an intersection
where a struck vehicle is hit approximately perpendicular to the
door by a striking vehicle thus compromising the integrity of the
occupant compartment of the struck vehicle. The collision can
deform the door into the occupant compartment and cause serious
injury to the occupant. The structure for use in an automobile for
protecting an occupant during a near side impact collision reduces
injury to a vehicle occupant resulting from a near side impact
collision between two vehicles by avoiding or reducing direct
contact of the door against the body of the occupant. In existing
occupant seating systems, the intruding door can cause serious
injury to the occupant's chest and pelvis from direct contact with
the door and the arm rest on one side and contact with the center
console on the other side. Since the injury is caused by a direct
intrusion of the door, an embodiment of the present invention
provides a structure for use in an automobile for protecting an
occupant during a near side impact collision that displaces the
occupant away from the incoming door panel using the contact
between the door panel and the seat structure instead of the door
panel against the occupant's body. Since the center console can
play a role in some pelvic fractures, the secondary load from
pelvic contact with the center console can be reduced by changing
the console structure, so that it yields under loading by the
pelvis. Furthermore, if the seat can move laterally in a controlled
manner into the space occupied by the crushed console, then primary
impact loads on the pelvis from contact with the door can also be
reduced.
[0013] A structure for use in an automobile for protecting an
occupant during a near side impact collision is provided to reduce
direct contact of the door against the body of an occupant and
resulting injury in a near side impact collision between two
vehicles. The structure prevents or reduces injury to the
occupant's chest and pelvis caused by direct intrusion of the door.
The structure provides three subsystems: (1) An occupant seat
mounted on a frame platform that maintains the geometry and
integrity of the seat and the occupant space upon contact by the
door during a side impact; (2) A seat track attached to the frame
platform to allow the frame and seat to translate laterally; The
occupant, frame, and seat contact a limiting barrier comprising a
door side panel and a center console side panel that compress or
crush upon impact absorbing the lateral translation of the seat and
frame platform; and (3) A restraint to ensure that the occupant
remains with the seat as it translates.
[0014] FIGS. 1, 2, and 3 show aspects of a structure for use in an
automobile for protecting an occupant during a near side impact
collision. FIG. 1 is a front view of a driver's seat. FIG. 2 is a
side view of the same seat. FIG. 3 shows the possible configuration
of the vehicle interior after a side impact collision. In FIG. 1,
standard components of an automotive vehicle include the driver's
door 1 in contact with the floor sill 2. Forward/rear adjustable
seat tracks are shown for the right track 3 and left track 5. The
components of the structure embodied in the present invention
further comprise three aspects.
[0015] A first aspect of the structure maintains the geometry and
integrity of the seat and therefore the occupant space as it is
contacted by the door during a side impact. Depending on the nature
of the collision and the size of the striking vehicle, the seat and
supporting frame members maintain the rigidity of the seat and
present sufficient surface to accommodate the highly variable
contact forces transmitted from the door as it is deformed by the
striking vehicle. These forces result in displacement of the seat
laterally. This subsystem comprises the seat forward/rear platform
18, the seat platform 17, the seat, right 10 and left 12 vertical
members, the lower 13, middle 9, and upper 11 cross members, which
together make up the seat structure. An occupant seat is mounted on
a rigid seat platform 17. The rigidity of the occupant seat is
maintained by the seat platform 17 which is attached to the right
seat vertical member 10 and the left seat vertical member 12. The
seat platform 17, right 10 and left 12 seat vertical members are
further reinforced by the lower cross member 13, the middle cross
member 9, and the upper cross member 11. In one embodiment, the
reinforcing members are external to the occupant seat.
Alternatively, various means of internal reinforcement of the
occupant seat can support the rigid frame members as the occupant
seat is mounted on the seat platform to maintain an occupant space
within an occupant compartment. The occupant seat can be rigid
depending upon the amount of internal reinforcement of the seat
itself and can be mounted directly to the lateral track.
[0016] A second aspect of the structure allows the seat to
translate laterally toward the center of the occupant compartment
upon a near side impact collision. The subsystem for lateral
translation comprises the lateral seat track 6 held by the lateral
seat track retainer 7 and attached to the seat platform 17. The
seat track 6 guides the seat platform 17 laterally. An additional
center forward/rear seat track 4 and shear bolts 8 control the
force at which the seat starts to slide. The front (not shown) and
rear console side panels 16 provide limiting barriers which crush
and absorb energy as the seat displaces laterally so that the
lateral motion of the seat is controlled. The center seat track 4
helps to stabilize the structure in anticipation of the left seat
track 3 being deformed during the collision. In one aspect, the
lateral track 6 supporting the seat frame 17 is cantilevered to
allow for deformation of the seat forward/rear platform 18 and the
left seat track 3 upon collision impact without displacing the
lateral track. The cantilevered lateral track allows the seat frame
and seat to translate laterally without displacement to or
distortion of the lateral track upon side impact collision. A
"cantilevered lateral track" refers to a projecting track that is
supported and restrained at one end only. In a further aspect, the
track extends about one half the width of the seat beyond the edge
of the seat. During a side impact the floor tends to buckle so a
full width track would probably distort, making sliding of the seat
problematic.
[0017] A third aspect of the structure ensures that the occupant
remains with the seat as the seat translates laterally during a
near side impact collision. An occupant restraint apparatus is
provided which comprises a seat arm rest/occupant guard 14 which
hinges with the right vertical member 10 to allow the occupant to
enter and exit the seat. The console/seat vertical panel 15 forms
the occupant's side of the center console and absorbs the impact of
the seat and occupant toward the center of the passenger
compartment upon impact and against the limiting barrier, e.g., the
center console of a crushable material. The console/seat vertical
panel 15 prevents movement of the occupant out of the seat and
towards the center of the passenger compartment. The seat arm
rest/occupant guard 14 prevents the occupant from moving towards
the door, and prevents direct contact of the occupant with the
door. The armrest, instead of being a source of protrusion on the
door panel, now moves with the seat and the occupant. In addition,
a standard 3-point lap and shoulder belt is attached to the seat to
further restrain the occupant in the standard manner.
[0018] FIG. 3 shows a front view of the structure after side impact
collision. The door 1 has impacted the rigid seat frame 10 and the
occupant impact guard 14 to overcome the shear release bolts 8 and
to move the seat frame laterally along the lateral seat track
toward the center of the occupant compartment. The seat frame 12
has contacted the console/seat vertical panel 15. The force of the
lateral movement is absorbed by the console transverse crushable
panel 16.
[0019] Studies of side impact injury reduction have focused on
several aspects to improve safety. Increasing the rigidity of the
door using a side impact beam reduces its intrusion into the
occupant space. However, since the position of the beam is aligned
with the height of the typical passenger vehicle bumper, it is less
effective for higher bumpers such as those of SUV's or light
trucks. There is also a limit to the increase in strength of the
door that can be gained by reinforcing it, considering the effects
of added weight. In addition, it is important to allow some crush
of the door to absorb energy of impact, otherwise the occupants
will be exposed to high acceleration levels. As the door becomes
stiffer it becomes necessary to reinforce the A pillar (between the
door and the front window) and the B pillar (between the front and
rear doors) and the floor sill to accommodate the stronger door,
further increasing the weight of the vehicle. Nonetheless, door
beams are now required by federal law in all vehicles. While this
has decreased intrusion, 25-35 cm of intrusion has been observed in
actual crashes, partly because of the mismatch in bumper height and
vehicle mass when a light truck or SUV hits a passenger car.
[0020] Considerable study has been given to different types of
padding of the door, with many vehicles now offering a thoracic
airbag that deploys from the side of the seat to reduce the
concentration of force against the occupant's chest. Studies have
show debatable effectiveness of these devices. In one study,
measurements in crash dummies during federal side impact crash
testing showed that accelerations were reduced only about 15%. More
importantly, acceleration from side impact crash stayed above
levels known to cause serious thoracic injury. There is concern
that a thoracic airbag, firing into the chest of an out-of-position
occupant, such as one leaning against the door, may in fact cause
rib fracture. An alternative is adding padding to the door. This in
general distributes the forces over the chest but does not decrease
door intrusion and may increase compression of the rib cage.
[0021] Finally, studies have considered widening the space between
the occupant and the door. If the space were widened by 25-35 cm.
it is possible to prevent much of the intrusion of the door into
the occupant space in many side impact crashes, reducing injury
potential. However, practical considerations, such as limits to
road width make this approach impractical. In one embodiment of the
invention, additional space in the center of the vehicle between
the two seats is available which is not used currently for side
impact protection. A structure for use in an automobile for
protecting an occupant during a near side impact collision, a
system for managing an occupant in an occupant compartment of an
automotive vehicle in an event of a near side impact collision, and
a method for managing an impact load from a near side impact
collision utilize the space in the center of the vehicle to
maintain an occupant space during the crash. In further
embodiments, the structure, system, and method comprise the
following components, which can be designed in a number of
ways.
[0022] a) A rigid perimeter frame for the seat that allows the door
to contact the occupant seat instead of the occupant and the seat
maintains its original shape without crushing. The rigid perimeter
frame can be external or internal to the occupant seat. This
includes a moveable armrest/occupant chest guard which ensures that
the door contacts the seat frame and not the occupant's chest or
pelvis.
[0023] b) A cantilevered track that allows the seat to displace
laterally when pushed by contact between the door and the seat
frame. Many alternative designs can be envisioned. In one
embodiment, the track is a simple guide slot. In a further
embodiment, the track extends about one half the width of the seat
beyond the edge of the seat. The seat is therefore cantilevered
from the track. During a side impact the floor tends to buckle so a
full width track would probably distort, making sliding of the seat
problematic.
[0024] c) A mechanism to ensure some resistance to lateral sliding
so that the seat maintains its position during normal use or in
other crash directions. In one embodiment, resistance to lateral
sliding is created by bolts which extend through the slotted track
guides with nuts torqued to a specified value, thereby providing
frictional resistance to lateral movement of the seat.
[0025] d) A crushable center console allows the seat to displace
laterally into the center of the vehicle and absorbs the lateral
translation of the seat and platform.
[0026] The following examples of specific embodiments for carrying
out the present invention are offered for illustrative purposes
only, and are not intended to limit the scope of the present
invention in any way.
[0027] The disclosures of all publications, patents and patent
applications cited herein are hereby incorporated by reference in
their entirety.
EXEMPLARY EMBODIMENT
Example 1
Experimental Testing
[0028] SINCAP side impact tests performed by the National Highway
Traffic Safety Administration (NHTSA) on vehicles from 1999-2003
were studied from data available at www.dms.dot.gov, docket 3835,
where complete reports of each test are posted. A total of 165
separate tests were analyzed. From the data, mean time histories of
door velocity and pelvic acceleration were generated to provide a
comparison from experiment and modeling shown herein to data from
controlled crashes.
[0029] The experimental apparatus consisted of a pendulum carrying
a pre-crushed door, a US DOT SID dummy, a seat, and a mechanism to
stop the motion of the pendulum after dummy impact. A door from a
1997 Toyota Celica was selected from wrecking yard vehicles
(Pull-Apart, Lynnwood Wash.) that had sustained an approximately 90
deg side impact with predominant deformation of the door located in
the rear half. A crushed door is necessary to simulate the actual
door stiffniess during contact with the occupant.
[0030] The apparatus consists of a simple pendulum composed of 2,
4.9 m long sections of 0.15 m.times.0.15 m.times.0.006 m
(6''.times.6''.times.1/4'') aluminum angle bolted together. One end
was mounted through a hinge to a frame bolted to the ceiling of the
lab. The other end was pulled upwards by a winch and cable system.
The door was mounted to the pendulum through an apparatus that
could change its orientation both vertically and horizontally. The
top of the arm rest was positioned level with the pelvis of the
dummy at contact. Two springs which could be precompressed were
used to stop the forward travel of the pendulum after contact with
the dummy. From 165 US DOT New Car Assessment Program (NCAP) tests,
the mean door peak velocity was 8.1 m/sec (range 2.8-13.4 m/sec)
and maximum intrusion was 34.4 cm, with a mean initial door to
dummy clearance of 15.1 cm giving a mean door-to-dummy contact
stroke of about 19 cm (11). Pendulum contact velocity was 6.3 m/sec
with a door-to-dummy stroke of 15 cm.
[0031] USDOT SID dummy (S/N 344 calibrated by Robert Denton, Inc,
Michigan) was selected for the experiment because it is used in the
SINCAP tests and therefore allowed a direct comparison of TTI and
pelvic acceleration from this experiment to SINCAP full scale test
results. The dummy was restrained with a lap and shoulder belt
fixed to the seat. Accelerometers were fixed to the T4, T8, and T12
rib levels and at the pelvis in the standard mounting positions on
the dummy.
[0032] The seat was designed to test the configurations of a
standard fixed seat, which crushed during impact with and without a
console, as well as a laterally translating seat with no console.
The seat frame was constructed so the half away from the door was a
rigid frame and the half towards the door was a moveable frame
which could slide over the rigid half. This allowed the half of the
seat frame closest to the door to simulate seat crushing during
impact. The rigid part of the seat frame was mounted onto a slotted
track which allowed lateral (Y) displacement. To simulate the fixed
seat-no console condition, the seat was locked to the lateral track
and the moveable half of the seat frame was allowed to slide into
the rigid half frame. To simulate the fixed seat-with console
condition, an aluminum plate simulated the vertical plane of the
console into which the hip might be compressed and was bolted to
the seat frame. Finally, to simulate the translating seat, the
moveable seat half frame was locked in its outmost position, and
the whole seat allowed to slide on the lateral track. In this
configuration, the seat frame retains its original dimension and
the whole seat slides laterally. The seat track was designed to
accommodate 25 cm of lateral displacement. This was the mean
intrusion distance found from the CIREN crashes studied and also
represents a common dimension between seats in many vehicles.
[0033] Data collection was performed at 10 KHz (National
Instruments, Austin, TX). High speed video (Kodak Ectapro, San
Diego, Calif.) running at 1000 frames/sec was used capture each
impact. Data from the accelerometers was filtered using the FIR 100
filter. Maximum and minimum accelerations from each test were
determined from the time history and the three conditions were
compared using a nonparametric Wilcoxon signed rank test small
samples with a significant difference set at p<0.05. The
pendulum tests were reproducible with a coefficient of variation in
peak pelvic acceleration of 0.074 (standard deviation/mean). With a
fixed seat and no console, the maximum pelvic acceleration due to
contact from the door was 28.5 g and the minimum (due to the lap
belt) was -3.3 g. With a console plate added, the maximum
acceleration was 24.8 g (not significantly different) while the
minimum acceleration due to contact with the console increased to
-10.5 g (p<0.05). With a seat allowing lateral movement upon
impact, with no console, the maximum pelvic acceleration decreased
to 15.3 g (p<0.05) and minimum acceleration remained at -3.8
g.
Example2
Development of a MADYMO Model of the Pendulum Side Impact
[0034] A USDOT SID version of a MADYMO.COPYRGT. model was developed
to allow direct comparison with the previous results of the USDOT
SID. ES-2, BIOSID and SIDiis versions of the model were used
because of their reported greater biofidelity (19,20).
[0035] The door was modeled by first testing its local stiffness in
the following manner. The door was mounted horizontally onto a
cradle with its interior surface facing upwards. A grid, 2 cm
square was drawn on the surface of the door and the center point of
each grid located at the crossing of diagonals on each square. The
door and cradle was mounted to the table of a materials testing
device. A 2.5 cm diameter cylindrical load tip was screwed to the
base of the load cell. The door was tested nondestructively at low
loading rate. Door interior panels, made of ABS, are relatively
insensitive to loading rate and can be characterized by quasistatic
or low rate loading (21). The tests were run under displacement
control to a maximum displacement of 2 cm at all grid center point
locations. The data was collected, at a sampling rate of 1000 Hz,
force-deflection data were plotted, and a stiffness map of the
interior door surface panel created. In addition, the displacement
at which the load first increased from zero was defined as the
contact point, from which a geometric profile map was plotted.
[0036] The door was represented in the model as a series of
translational joints of prescribed stiffness based on the
mechanical testing described above with a finite element mesh of
shell elements as the door contact surface to the dummy. The door
surface, being coarser, was selected as the master surface and
finite element meshes were created to coat around the dummy's
ellipsoid contact surfaces. The seat consisted of shell elements,
with a center console plane, fixed to the reference space. The base
of the seat was connected to the reference space by a joint
allowing translation in the Y (lateral) direction, representing the
seat track. The USDOT SID dummy was restrained by a finite element
lap belt. The seat/dummy friction coefficient was set at 0.3. Both
the model and experiment represented a passenger's side impact.
[0037] For the case of the standard fixed seat, the seat stiffness
(for door contact) was 1.times.10.sup.2N/mm, the seat joint was
locked (no translation), a console plane was added, and the door
configuration was as shown previously. For the translating seat,
the seat stiffness was increased to 1.times.10.sup.3, the seat
joint was unlocked with a frictional coefficient of 0.3, along with
a shear release load of 5000N, and the door panel was flat with a
narrow arm rest. The pelvic contact forces were compared for the
two cases studied.
[0038] For this part of the study, focusing on pelvic loads,
results from USDOT are presented to show conceptually how the seat
and the environment can be altered. Results with other dummies were
similar. A comparison of pelvic accelerations between the model and
experiment and with mean data from SINCAP tests was performed. A
small amount of drag was added in the model to reflect friction in
the experimental apparatus. With this, the model and experiment
were in very good agreement, both for door velocity and pelvic
acceleration. SINCAP values were higher with mean peak door
velocity of 11.1 m/sec (mean -1sd=8.4 m/sec). Pelvic acceleration
was also higher. However, SINCAP test results had a very wide
variation (2.8-13.4 m/sec for door velocity and 19-145 g for peak
pelvic acceleration.
[0039] The pelvis can become trapped between the incoming door and
the console in the case of a fixed, deformable seat and a rigid
console relative to the pelvis. Forces are generated in the two
cases. The fixed seat results in high door to seat loads and the
initial door to pelvis contact force was in the range of
10.times.10.sup.3 N. When the pelvis contacted the console, the
second force on the pelvis peaked at about 20.times.10.sup.3 N. In
contrast, with the stiffer translating seat and no console, the
initial pelvic contact force was much lower, about 4.times.10.sup.3
N and there was no secondary force since there was no pelvic to
console contact.
[0040] Although the present invention has been described in
connection with particular embodiments thereof, it is to be
understood that various modifications, alterations, and adaptations
may be made by those skilled in the art without departing from the
spirit and scope of the invention set forth in the following
claims.
* * * * *
References